Digester



2 (No Model.)

' E. MEURER;

DIGESTER.

No. 592,875. Patented NovrZ/1897,

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UNITED STATES PATENT FFICE.

EUGENE MEURER, OF PALMER FALLS, NEW YORK.

DIGESTER.

SPECIFICATION forming part of Letters Patent No. 592,875, dated November 2, 1897.

Application filed March 28, 1895. Serial No. 543,536. (No model.)

To all whom it may concern.-

Be it known that I, EUGENE MEURER, a subject of the Emperor of Germany, residing at Palmer Falls, in the county of Saratoga and State of New York, have invented a certain new and useful Improvement in Digesters, of which the following is a full, clear, and exact description.

My invention relates specially to the digesters that are used for converting wood into pulp for the manufacture of paper and similarpurposes; and, generally stated, it consists in such a construction of the blow-off apparatus that the contents of the digester, consisting of a mingled mass of acids, pulp, and

gases, will be thoroughly mixed with .water while passing through the blow-off pipe leading from the digester to the washing-tank.

In the usual methods of treating wood for converting it into pulp a high pressure is adopted, varying from forty to seventy-five pounds to the square inch, and as a result when the discharge-valve is open the contents of the digester are discharged into the receiving-tank with great force. As is well known, the chemicals that are used in the cooking process give rise to very offensive odors, and various methods have heretofore been resorted to to kill the odors that are liberated by the discharge of the pulp into the blow-off tanks. The usual way has been to condense the gases and steam in the tank itself, but for this purpose a very tight tank is required, and as these tanks are usually made of wood it is very diflicult, on account of the chemicals used, to keep them from leaking.

The present invention seeks to obviate the disadvantages to laborers and to the sur rounding plant arising from the escape of the corrosive and poisonous gases, and this is accomplished by efiecting the condensation of the gases in the blow-pipe itself before the mass under treatment reaches the tank.

The invention is illustrated in the accompanying drawings, in which- Figure 1 is a view showing the digester, the tank, and the connecting blow-off pipe; and Fig. 2 is a view in section showing the construction of the blow-off pipe itself.

In the figures, A is the digester, B the tank, and O D the blow-off pipe. This blow-off pipe is made up of two sections arranged concentrically, but of different diameters, so that the outer section D forms a casing for the inner one, with an annular space between the two. Connected with the casing D is a water-inlet E, provided with any suitable valve F. Preferably this casing is contracted just beyond the water-inlet in the direction of the discharge, and the section 0 extends beyond the water-inlet just far enough to give direction to the flow of the water, but it terminates before the tank is reached, thus leaving in the pipe-section D a clear space in which the water and the pulp and gases are freely and thoroughly mingled. Communication between the digester and the blow-off pipe is controlled by the valve G.

In blowing out a digester in which this invention is embodied the blow-out valve of the digester and the water-inlet valve are to be opened at the same time. The force with which the contents of the digester rush through the pipe 0 tends to create a strong vacuum in the annular space surrounding such pipe, and this draws in the water through the inlet E. This water becomes thoroughly commingled with the hot pulp in the outer end of the pipe D and condenses the steam and the gases before the mass enters the tank. This water of course drains off from the pulp through suitable perforations and discharge pipes in the bottom of the tank, as in the case of the water used in washingthe pulp in the tank by existing processes.

The improved mode of treatment by the abovedescribed apparatus has proved in practice so efficient that it is found no longer necessary to attempt to make the blow-off tanks tight. On the contrary, it is entirely feasible to leave-an opening in the top of the tank communicating with the surrounding air of the factory.

The construction above described represents the best form in which the invention has been embodied; but it will be seen that instead of extending the pipe 0 some distance into the pipe'D, so as toform an annular space between them, as shown in Fig. 2,

the pipe 0 might be stopped off. at a point pulp, respectively, will meet at right angles with great force in the confined space within the blow-oil": pipe, and thus will become thoroughly commingled before being discharged into the tank. Such a construction, however, would not be as economical as that shown in the drawings and would involve greater wear of the parts.

\Vhat is claimed as new is- 1. In combination with the blow-off pipe of a pulp-digester, a water-inlet communicating with the blow-off pipe at a point intermediate of its connection with the digester and its discharge end, whereby a supply of wateris furnished to be mingled with the contents of the digester in their passage through the blow-off pipe, substantially as and for the purpose set forth.

2. In combination with a pulp-digester a blowoff pipe, consisting of two sections arranged concentrically with an annular space between them, and a water-inlet connected to the outer section of the blow-oil? pipe at a point intermediate of the free end of the inner section thereof and its connection with the digester, substantially as and for the purpose set forth.

EUGENE MEURER.

Witnesses:

SAML. A. DUNCAN, Rom. F. GAYLORD. 

